Backported from X.org (+ coding style fixes in other free() calls):

 commit 617b7d22115ccaaaa7ec69c99885054d33a3bc37
 Author: Pauli Nieminen <ext-pauli.nieminen@nokia.com>
 Date:   Thu Dec 30 19:19:42 2010 +0200

    os: Fix a memory leak
Signed-off-by: Pauli Nieminen <ext-pauli.nieminen@nokia.com>
Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>
Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>